Well-drilling machinery.



W. A. MCCAUSLAND.

WELL DRILLING MACHINERY.

4APPLICATION man Mln/11.1916.

PatentedV Jan. 2, 1917.

5 SHEETS-SHEET l.

fd f;

Wl Til/ESSE l er A AHORA/frs W. A. MCCAUSLAND. l WELL DRILLING MACHINERY. APPLICATION FILED MA1/I1. 1916.

Patented 1.1112191?.

5 SHEETS-sniff 2. l

III IIIII# Patented Jan. 2,'1917. 5 SHEETS-SHEET 3.

W. A. McCAUSLAND.

- v WELL DRILLING MACHINERY.

A APPLICATION meu MAY 17, 1916. 1,21 1,199.

AHORA/frs W. Ax McCAUSLAND.

WELL DRILLING MACHINERY.

eAPPLICATION FILED MAY l1. 191s.

Patented Jan. 2, 1917.

5 SHEETS-SHEET 5.

Mm y

A TOH/VEYS iiNrr srs WELL-DRILLING MACHINERY..

Specification of Letters Patent.

Patented J an. 2, 191 2.

Application filed May 17, 1,916. Serial No. 98,069-l T 0 aZZVwto/m t may concern:

Be it known that I, WILLIAM A. MoCA-Us- LAND, a citizen of the United States, anda resident of Pittsburgh, ink the county of Allegheny and: State of Pennsylvania, have invented a certain new and useful Improve-v ment in TWell-Drilling Machinery, of which the following is a specification. 'l

My invention relates to improvements in well drilling machinery, and it consistsin the combinations, constructions, and arrangements herein describedV and' claimed.

An object of my invention is to provide a device which is so constructed that by 'its use the ordina-ry derrick is dispensed with.

A further object of my invention is' to provide a well drilling device which has a slidable walking beam mounted substantially at its central point when' the beam is being used in the drilling operation and capable of sliding with respect to the samson post so as to permitthe drawing of casings of greater length than could otherwise be drawn were not the beamsadjustable.

A further object of my invention is to' provideV a system of pulleys for effecting such operations as they raising of the casing, this system being carried on top 'of the walking beam itself and not Vbeing suspended from the endl `of the walking beam which is above the wellV hole. This removes the pulleys so that the full height between the ground line and the end of the walking beam above the well hole may be utilized. for raising casing sections.

A. further object of my invention .is to provide a novel form of means for feeding the tool forwardly, or backwardly, at will".

A further object of my inventionfis to provide a novel form of clutcl'i mechanism which coperates with the feeding mechanism in such a manner thatin `ord'e'r to op,- erate the clutch the feeding mechanism must be disengaged, while in order to operate the feeding mechanism the clutch` must be disengaged.

Other objects and advantages willv appear in the following speciiicat'ion, and' the novel features of the invention will be particularly pointed out in the appended claims.

My invention is'illfustrated in the accompanyingd'rawing forming part of' this application, in which: K

Y Figure 1 is a side elevation ofthe device showing the latter inposition for drilling a` well. Fig. :2 is a plan view ofthe walking beam. Fig, 3. is a sectional view along the line 3-3 of Fig. 1. Fig. 4 is a side view of thedevice looking from the opposite direction. Fig. 5 is an enlarged detail sectional lview through a portion of the samson post andthe walking beam, along'the line 5 5 of Fig.8. l Fig. 6 is a bottom plan viewof a portion ofthe Walking beam. Fig. 7 is a sectional' view through a portion of the walkingv beam. Fig. 8 is a sectional view through the walking beam and a portion of the Samson post at right angles to that shown in'F ig. 5. Fig. 9l is a section along the line 9-9 of Fig. 4. Fig. 10 is a section alongthe line '1G-10 of Fig; 11. Fig. 11

is an end 'view of the feed and clutch mech-- anism. Fig. 12 is a section along the line 12-1'2 of Fig. 10.V Fig. 13 is a perspective viewV ofv a portion of 'the device shown in Figs. 11 and 12. Fig. 14 is a side view of the device showing f the walking beam in its shifted position. Fig; 15 isa view of a portion o-f the end of the .walking beam, certain 'parts being broken away.

In carrying o-ut my invention `I provide a base 1, composed of longitudinal beams se? cured` .together by cross beams. Upon this base is mounted the samson post 2 which is suitably braced by inclined vbraces 3. As will be seen from Fig.A 5, the Samson post 2 is slotted, as shown at l. Side plates 5 are secured to the upper end of the samson post, these side plates forming bearings for a shaft G, see Fig. 8, which is provided with a gear 7 disposed in the slot A. The outer end of the shaft 6 bears a small drum 8 upon which is wound a cable 9 whose uw.; will be explained later.

A walking beam 10 surmounts the samson post 2. As will be seen from Fig. 5, the

walking beam has a cut away portion 11 in which is disposed a rack 12, the rack f running longitudinally withrespect to the walking beam and being disposed in a plane with itsy central vaxis; At' 13 and 1A are transverse members which are set into the bottom of the walking beam and which eX- tend below the surface thereof, these members supporting cylindrical guide rods la,

IGS

which is secured to the pawl and extends above the shaft 19, as shown in Fig. 7, so that when the pawl 20 is pulled downwardly, the spring is flexed by its engagement with the shaft. A spring 215' is secured to the pawl 21 and operates in a similar manner to keep the pawl in an upper position. The plate 16 is provided with recesses 16", see Fig. 7, into which the hubs of the pawls 2b and 21 extend, so that the plate 16 is virtually fixed with respect to the shaft 19, and the pawls 20 and 21 which are mounted on the shaft. The walking beam 10, however, has a movement relative to the plate and. to the pawls.

Considerl now Figs. 1 and 5. The walking beam is shown in substantially a central position in which the well drilling process is carried on. ln this position the pawl 21 engages the cross member 13, but if the pawl is released by a pull on the rope 22, see Fig. 5, and the cable 9 should be manipulated to rotate the drum-8 and the gear 7 in the direction shown in Fig. 5, then the beam would be shifted toward the left in Fig. 5, or toward the right in Fig. 1, through the medium of the gear 18 and the rack 12, until the pawl 20 engages the cross member 14, see Fig. 14, when the device would be in the position for drawing the tool from the well. T he means by which this is done will be explained later. ln the normal operation of the machine it will be apparent that the walking beam is pi'votally mounted with respect to the axis of the shaft 19, since as the beam oscillates it will cause a slight rotary movment of the gear 18 about the shaft 19, and also of the gear 7 and the shaft 6. The movement of the shaft 6 however will be comparatively small.

Mounted on uprights 23 carried by the base 1 is a shaft 24, bearing a drive wheel 25, which may be driven in anysuitable manner, as by a belt 26. Loosely mounted on the shaft 24 is a reel or drum 27 at one side of which there is a wheel 28 having a band brake 28il arranged to coperate with the wheel. The wheel 2S forms in fact one side of the reel. Secured to the wheel 28 is a worm wheel 29, see Figs. 11 and 12, through the center of which the shaft 24 passes. This worinwheel is designed to be engaged by the teeth 30 of a clutch member 31 which consists of a collar feathered to the'shaft 24 so as to slide longitudinallyT with respect to the latter but to be rotated by the rotation of the shaft 24. rlhe collar is prcvided with a yoke 32 which is slotted at its ends to receive the pins 33 of a ring 34. The yoke 32 is mounted on a rock shaft 35 which extends forwardly and by means of which the clutch member 31 may be brought into operative engagement with the gear 29 so as to cause the rotation of the latter, and hence of the drum 27.

The drum 27 may be rotated in either direction manually, and to accomplish this I provide an upright 36 which is secured to the base 1 and which is provided with a slidable member like that shown in Fig. 13, this slidable member having a base 37 with an opening 37X arranged to fit over the upright 36, and it is provided with two supporting arms 38 arrangedto receive a rock shaft 39 bearing a worm 40 which is disposed between the members 38 and which, under certain conditions, is designed to engage the worm wheel 29. An L-shaped stop member 41 is carried by the slidable member and the upper end of the L-shaped member 41 projects overthe top of the standard 36 in the manner shown in Fig. 12.

1n Fig. 10 it will be observed that the lower part of the member 37 is engaged by 3 a bell-crank lever 43 which is pivoted at 44 and whose long arm is operated by ropes or cables 45, leading to the front part of the device, these ropes being secured for convenience to a handle 46 on the rock shaft 35.

In Fig. 10 the bell crank lever is in the i position to hold the slidable member 37 in an upper position, thereby bringing the worm 40 in operative relation with the worm wheel 29. lf now the shaft 39 is rotated then the drum will be moved in one direction or the other, according to the rotation of the shaft. It will be observed from Figs. 10 and 11 that the arm 41 extends up into the path of the collar 30, so that itis im possible to operate the clutch member while the worm and gear are in operative relation. The only way to connect the clutch member is to manipulate the rope 45 so as to swing the bell crank lever to such a position that it will permit the member 37 bearing the worm 40 to descend until 'it is resting against a stop pin 47, see Fig. 12. In this position, it will be observed that the worm and gea-r are disconnected, and that the stop arm 41 has moved out of the path of the collar 30, thereby permitting the operation of the clutch. It will be seen that, when the worm and gear are in connection, the clutch cannot be operated, and that when the clutch is operated, the worm and gear cannot be in connection. This absolutely prevents any breaking of the machinery through the engagement of the clutch and the worm and gear at the same time. The drum 27 is proprovide a countersunk hook 56x on the wheel 28 to which the e-nd of the cable 56 may be attached in such a manner that when the drum is turned, the cable 56 may be wound up or unwound, depending upon the direction of rotation of the drum. The cable 56 passes upwardly over a pulley 57,'thence forwardly around the pulley in the slidable pulley block 58, thence around the pulley 59 which is fixed to the walking beam 10, thence forwardly around the other pulley to the pulley block 58, and thence rearwardly, being fastened to the frame of the .pulley 59. The pulley block 58 is provided with a U- shaped guide frame 58X by means of which it may be moved forwardly and backwardly along the walking beam 10. The cable 58 is secured to the slidable pulley block 58 and passes forwardly over a pulley 60 just underneath the pulley 51 and is clamped to the tool holding cable 49 when the well is being drilled. A second cable 61 is fastened to the pulley block 58, passes forwardly over a pulley 62, and thence downwardly to the end of the cable, being loosely supported by the hook 63, see Fig. 4, until it is desired to make use of this cable, as will be explained later.V

From the end of the shaft 24 is an arm 64` having a crank pinY 65 toV which a flexible rope or cable 66 is connected, the upper end of this cable being secured to the end of the walking beam 10. This is the Cable which operates the walking beam. The slackof the cable is taken up by a counterwei-ght 67 which is connected to the cable 66 by means of the flexible member 68. At 70 I have shown an extensible hook which is pivotally mounted upon the frame l of the device ano which is held in the position shown in Fig. 1 by a flexible member Tlsecured to one of the uprights or to the samson post 2. At 72 is shown a U-shaped hook or eye which -is arranged to engage the hook 70 in the arm 64 which draws downwardly on 'the' walking beam 10. l7l/*hen the crank Iarm passes the limit of its lower position, the tool will suddenly drop, the weight 67 taking up the slack in the cable 66, while a counterweight (not shown) at the end o f the flexible member 55 takes care of theY slack in the cable 49. It is only necessary to turn the handle 39x of the control shaftv 39 f to feed the tool forwardly or backwardly as desired, since this will turn vthe drum through the medium of the worm and gear.

s the feed rod 39 is turned, the cable 56 is Agradually paid out. This permits the slid'- able pulley block 58to move along the walk- '58@ ing beam .from the vleft to the right, in aj progressive movement. Of course as the walking beam reciprocates, this pulley block slides back and forth in a slight reciprocatory movement. As the cable 56 is let out, the cable 49 has its slack taken up to a considerable extent, but not wholly. Now when the pulley block 58 has reached the limit of its movement, 2'.. c., whenV it is close to the pulley 51, then the clamp 52 is loosened and the drum 27 is reversed so as to draw back the pulley block 58 to the left end of the walking beam, and at the same time let o-ut more length of the cable 49. The cable 58 is now clamped to the cable 49 at a point just below the walking beam.

Right here I desire to call' attention to the utility of placing the slidable pulley block on the walking beam. rdinarily the pulley block is located beneath the end of the walking beam just above 'the well, but it will be obvious that the space taken up by the system of pulleys in the ordinary construction is gained in my construction.

Then the well has been drilled to the depth desired, or when it is otherwise desired to remove the welltool, the'clamp 52 is unloosened from the cable 49, the free end of the cab-le 56 is detached from i-tshook 56", the cable 56 is unwound from the drum. The slack holding member 55 is removed, the rope 45 ispulled'so astothrow off the worm and gear in the manner already del scribed, and then the rod 85 is turned so as to throw in the clutch member 30. The drum may now be rotated so as to wind up the cable 49, thus drawing up the tool.V lf the tool shouldbe'a very heavy one, it may be raised with the blockan'd: tackle arrangenient which is used for drawing up the casing. Y

1n order to provide suflicient height forV lifting up casingsections and also for drawingvthe well tools if'desired, l make use of the shiftable rocking beam. To this end, while Vthe shaft 24 is in rotation, the ,flexible cable 9 whose end is wrapped around the brace rod, in Fig. ,1, is removed from the latterv and is given a Vtwist around the shaft 24 and drawn with suflicienttightness so as to cause a rotation of the shaft 6, see Figs. 1 and S, thereby causing the movement of the r-ralking beam through the medium of the gear '18 and the rack 12 from the position shown in Fig. 1, to that shown in Fig. 14. lt will be understood that, prior to the niovement of the walking beam, the left hand end of the beam, as shown in Fig. 1, is pulled downwardly, the tool having been drawn and there being substantially no weight on the opposite end. This downward movement of the left end of the walking beam in Fig. 1, will cause the block 13, see Fig. 1, to clear the locking pawl 21, which ywill be` held by' the short flexible member 9.2. This member 9.2 is sufficiently long to permit the ordinary oscillation of the walking beam without withdrawing the pawl, but when the walking beam is pulled downwardly preparatory to a shifting move ment, then the pawlis withdrawn from the block 13 so as to permit the movement to take place. The beam is moved to the position shown in Fig. lil, where it is held by means of the pawl 20 which engages the block 111-. Alt the same time the hook 72 en gages the hook 70, thereby holding the walking beam rigidly Vin its shifted position. [is stated before, the tool may be drawn while the walking beam is in its upper position, or casings may be drawn. In order te draw a casing the cable 53 is secured to the casing, the pulley block 58 being in its forward position, z'. e., adjacent to the pulley 51, the drum 27 is rotated, the end of the cable 56 first being attached to the drum, so that the cable 56 will be wound up. The pulley block 5S will travel toward the left in Fig. 1, thus raising the casing, which owing to the additional height between the walking beam and the ground, can be made up of long sections.

It is often necessary to take a new hold on the casing by lowering the end of the cable 53, and securing it to the casing in lowered position. In order to move the pulley block from the left to the right, shown in Fig. 1, and thus lower the cable 53, I provide the cable 61 which may be wound around the shaft 24 in an opposite direction to that of the cable 56, the end being secured to a pin 61a. The rotation of the shaft 24 will wind up the cable 61 and pay out the cable 56, so that the pulley block 58 is pulled forwardly and the cable 53 is lowered. 1When this is done the cable 61 may be loosened from the shaft 24. The cable 53 may be fastened to the casing and another length may be raised in the manner described.

Vidhen it is desired to lower the walking beam from the position shown in Fig. 14 to that shown in Fig. 1it is only necessary to pull downwardly on the release rod or ycable 20a, when the weight of the beam will cause it to slide downwardly, disengaging the hooks and 72. As the walking beam descends it will tend to assume a more nearly horizontal position, since it is now free from the hook 72. This will bring into play the pawl 21, so that when the walking beam reaches the position shown in Fig. 1, the pawl 21 will spring into place behind the block 13 and thus hold it. The shifting of the walking beam may be accomplished in a moment, and as stated the device is locked automatically when it reaches the working position.

It will thus be seen that I have provided a device which dispenses with the necessity of a tall derrick, which provides a walking beam whose elevation can be made greater or less to accommodate long lengths of casing, whose available height is made greater by the fact that the block and tackle arrangement is carried on top of the walking beam and is not suspended from it. The feature of preventing injury to the machine by the locking of the clutch mechanism when the worm and gear is in operation, or vice versa,

is designed to save a great deal of trouble from inexperienced operators.

I claim 1. In a well drilling apparatus, a samson post, a walking beam pivotally mounted on said samson post, said walking beam being movable with respect to its pivotal support in the longitudinal direction of the beam.

2. In a well drilling apparatus, a samson post, a walking beam pivotally mounted on said samson post, said walking beam being slidable with respect to its pivotal support in the longitudinal direction of the beam.

3. In a well drilling apparatus, a samson post, a walking beam pivotally mounted on said samson post, said walking beam being slidable with respect to its pivotal support in the longitudinal direction of the beam, and automatic means for retaining the walking beam in its shifted position.

4i. In a Well drilling apparatus, a samson post, a walking beam pivotally mounted on said Samson post, said walking beam i" being` 'slidable with respect to its pivotal support in the longitudinal direction of the beam, and automatic means for retaining the walking beam in its shifted position,

said means comprising a spring-actuated -pawl arranged to engage a portion of the beam, a hook secured to the frame of the device, and a hook or eye secured to said walking beam and arranged to engage said first named hook.

5. In a well drilling apparatus, a samson post, a walking beam having a pivotal connection with said Samson post, said walking beam also being slidable with respect lto its pivotal connection, a spring pressed pawl for normally holding the walking beam in a central position during the normali reciprocatory movement of the walking beam,` means for disengaging the pawl from the walking beam when the latter is tilted to an abnormal position, and means for shifting the beam when the pawl disei-igaged therefrom.

6. In a well drilling apparatus, a samson post, a walking beam having a pivotal connection with said samson post, said walking beamr also being slidable with respect to its pivotal connection, a spring pressed pawl for normally holding the walking beam in a central position during the normal reciprocatory movement of the walking beam,y means for disengaging the pawl from the walking beam when the latter is tilted to an abnormal position, means for shifting the beam when the pawl is disengaged therefrom, and means for locking the walking beam in its shifted position.

'7. In a well drilling apparatus, a samson post, a walkingv beam pivotally and slidably mounted withl respect to said samson post, means for reciprocating the walk ing beam, means for shifting the walking beam longitudinali)Y of its axis, and means for retaining the walking beam in its shifted position. Y

8. In a well 'drilling apparatus, a samson post, a walking beam pivotally mounted thereon, a power shaft, a crank arm carried by said power shaft, a flexible connectionr between saidl crank arm and said walking beam for reciprocating the latter, a drum mounted on said power shaft, a clutch for imparting movementof the shaft to the drum, a cable wound on the drum, pulleys carried by the walking beam for receiving the cable, a second cable wound on the drum in the opposite direction from said' last named cable, a block and tackle device carriedf by said walking beam, on the top thereof, said block being slidable along the walkin-g beam, a cable secured to said slidable block, and a pulley carried bythe walking` beam: at the` end thereof for receiving the second cable, and means for clamping the second cable to the last named cable.

9. In a well drilling apparatus,v a sam-V son post, a walking beam pivotal'ly mounted thereon, a power shaft, a crank arm carried by said power shaft, a ilexible connection between said crank arm and said walking beam for reciprocating the latter, a drum mounted on said power shaft, a clutch for imparting movement of the shaft to the drum, a cable wound on the drum, pulleys carried by the walking beam for receiving the cable, a second cable wound on the drum in the opposite direction from said last named cable, a block and tackle device carried by said walking beam on the top therecf, said block being slidable along the walking beam, a cable secured to said slidable block, a pulley carried by the Walking beam at the end thereof for receiving the second cable, means for clamping the sec-V ond cable to the last named cable, andy auxi'liary means for sliding the block along the walking beam from one end' to the other.

10. In a well drilling. apparatus, a samson post, a walking beam slidable with re.

spe-ct to the samson post in the direction of the axis of the walking beam and having a 1pivotal connection with said samson post, a power shaft, adrum disposed on thepower shaft, a Clutch for imparting the movement of the shaft to the drum,l a cable wound on the drum and extending over pulleys on the walking beam, said cable being attached to the well drilling tool, a second cable wound on the drum in the opposite direction, a block and tackle arrangement carried by the walking beam on the vtop thereof one end of the block and tackle arrangement being connected to said second' named cable, the opposite end being clamped to the rst named. cable, means Connected with Said. power shaft for reciprocating the walking beam, and means for feeding forwardly the cable connected to the block and tackle arrangement.

ll. In a well drilling apparatus, a samson post, la. walking beam slidable with respect to the samson post in the direction` of the axis of the walking beam and having a pivotal connection with said samson post, a power shaft, a drum disposed on the power shaft, a clutchE for imparting the movement of the shaft to the drum, a cable Wound on the drum and extending over pulleys on the walking beam, said cable being attached to the well drilling tool', a second cable wound on the drum in the opposite direction, a block and tackle arrangement carried by the walking beam on the top thereof, one end of'the blockY and tackle arrangement being connected to saidv second named cable, the opposite end being clamped to the irst named cable,` means connected with said power shaft for reciprocating the walking beam, and means for feeding forwardly the cable connected to the block and tackle arrangement,` said last named meansfcomprising a wormand gear connection with the drum, l

12. In a well drilling apparatus, a samson post, a walking beam slidable with respect to the samson post in the direction of the axis of the walking beam and having a pivotal connection with said samson post, a power shaft, a drum disposed on the power shaft, a clutch for imparting the movement of the shaft to the drum, a cable wound on the drum and extending over pulleys on the walking beam, said cable being attached to the well drilling tool, a second cable wound on the drum in the opposite direction, a

block and tackle arrangement carried by the walking beam on the top thereof, one end of the block'and tackle arrangement being connected to said second named cable, the opposite end being clamped to the first named cable, vmeans connected with said power shaft for reciprocating the walking beam, means for feeding forwardly the cable connected to the block and tackle arrangement, said last named means comprising a worm and gear connection with the drum, and means for disengaging the worm from the gear.

13. In a well drilling apparatus, a samson post, a walking beam slidable with respect to the samson post in the direction of the aXis of the walking beam and having a pivotal connection with said samson post, a power shaft, a drum disposed on vthe power shaft, a clutch for imparting the movement of the shaft to the drum, a cable wound on the drum and extending over pulleys on the walking beam, said cable being attached to the well drilling tool, a second cable wound on the drum in the opposite direction, a block and tackle arrangement carried b y the walking' beam on the top thereof, one end of the block and tackle arrangement being connected to said second named cable, the opposite end being clamped to the first named cable, means connected with said power shaft for reciprocating the walking beam, means for feeding forwardly the cable connected to the block and tackle arrangement, said last named means comprising a worm and gear connection with the drum, and means for disengaging the worm from the gear, and a. clutch for connecting the drum directly to the shaft.

14. In a well drilling apparatus, a samson post, a walking beam slidable with 'respect to the Samson post in the direction of the axis of the walking beam and having a pivotal connection with said samson post, a power shaft, a drum disposed on the power shaft, a clutch for imparting the movement of the shaft to the drum, a cable wound on the drum and extending over pulleys on the walking beam, said cable being attached to the well drilling tool, a second cable wound on the drum in the opposite direction, a block and tackle arrangement carried by the walking beam on the top thereof, one end of the block and tackle arrangement being connected. to said second named cable, the opposite end being clamped to the first named cable, means connected with said power shaft for reciprocating the walking beam, means for feeding forwardly the cable connected to the block and tackle arrangement, said last named means comprising a worm and gear connection with the drum, means for disengaging the worm from the gear, a clutch for connecting the drum directly to the shaft, and means for preventing the engagement of the clutch when the worm is in en` gagement with its gear.

l5. In a well drilling apparatus, a sanison post, a, walking beam slidable with respect to the Samson post in the direction of the axis of the walking beam and having a pivotal connection with said Samson post, a power shaft, a drum disposed on the power shaft, a clutch for imparting the movement of the shaftto the drum, a cable wound on the drum and extending over pulleys on the walking beam, said cable being attached to the well drilling tool, a second cable wound on the drum in the opposite direction, a block and tackle arrangement carried by the walking beam on the top thereof, one end of the block and tackle arrangement being connected to said second named cable, the opposite end being clamped to the first named cable, means connected with said power shaft for reciprocating the walking beam, means for feeding forwardly the cable connected to the block and tackle arrangement, said last named means comprising a worm and gear connection with the drum, means for disengaging the worm from the gear, a clutch for connecting the drum directly to the shaft, means for preventing the engagement of the clutch when the worm is in engagementwith its gear, and for preventing the engagement of the worm and gear when the clutch is in operation.

WILLIAM AUGUSTUS MCCAUSLAND.

lVitnesses MICHAEL lVAGNEn,

J. G. KAISER.

'iopies of this patent may be obtained for ve cents each, by addressing the Commissioner of Patents, Washington, D. C." 

